I ended up replacing my MacBook Air at the Apple store around a month ago. Things were great until a few days ago, when the fan stared making lots of noise. Now it's spinning more slowely (2500 rpm), the CPU temperature is low (around 60c) but the slowdowns are back and right now kernel_task is taking up 140% CPU time. This is happening once or twice an hour.

I've been using Apple computers for a while, but I've never had as many problems as I do with the Air. Apple really has to come out and say that there are problems and offer up some solutions, because this just isn't working.

We all need to keep in mind this is minimalist computer with miniaturized components. But I do agree it is frustrating being an earlier adopter with the Air. I had initial issues with a 1.6/80, and overall believed it was under powered for 5% of the daily tasks for me. I am now using a 1.8Ghz/64SSD model and now 98% satisfied. The next model should be much better I would think.

I was having all kinds of issues with CPU usage, fans, etc. (even with the 1.8 at first), but seem to have stabilized the system. I ended up having to reinstall the entire system. I left out printer drivers, extra languages, etc. Even part of the iLife suite. I use Xslimmer to lean up all the apps, and relied on activity monitor to watch every process for a day or so as I rebuilt it. I found stable settings in coolbook. Left it to index spotlight for half a day. File vault is also working perfect. Also, no more unnecessary apps -- i.e. anything with a Microsoft logo on it (except for a Win XP bootcamp partition), and no games.

It now idles at 800Mhz and 43C as I type this post in Safari. The fans rarely turn on now, except when it indexes, moves/backups large amounts of data, HD video, or multi-task with too many apps. I hope Apple improves efficiency in Snow Leopard:)

I am sick of this frickin kernel task acting up. My ibook ran WoW better then this PoS. I know its not designed to game, but what is the point of have a 1.6ghz C2D if I cant use it? Might have well stuck with my G4. I dont even get a core shut down according to activity monitor, I just get kernel tasking hog the cpu. I have owned this computer for about 5 months do you think apple will let me exchange it for a macbook? I mean it does not perform as advertised. I have been using apple for years but this is the biggest pile of crap I have ever used, windows or mac. Is ask for an exchange out of the question?

People might wonder why trimming the apps would have an effect. The reason is that less background tasks will run, which leads to less CPU load, which leads to less heat. On my machine right now I have 291 threads in 70 processes. In general, background tasks are not supposed to consume any significant portion of CPU, especially when they are idle. But as xolox notes, trimming back the number of apps (and thus background processes) does have a cumulative effect in lowering the running temp of the system. Thanks for posting that result.

I have the exact same problem with my mba getting hot and fans running at full speed while slowing down the computer completely. I called Apple and they sent me an application to capture data for Apple Engineering and I have emailed them the captured process.txt file for review. They definitely found something alarming in safari taking up almost 90% of cpu. I am waiting for a call from them. Will post the results.

My symptoms were a slowdown after running for a while displaying HD video For example, I can watch HD trailers from the Apple site for about 10 minutes before the computer heats up so much that it slows itself down so that the frame rate is about 4fps. At the start it can play smooth, full-screen, HD video at 23.98fps, the way it is supposed to be.

I just got off the phone with AppleCare, I complained about the behavior, they forwarded it to Engineering, who said that this is to be expected from this computer.

Would I have bought a MacBook Air (or kept it) if I had known that it isn't expected to perform at full capacity for longer than 10 minutes? I rather doubt it. Can I do anything about it now? Probably not. Will Apple fix it? Well, they introduced new Mac Book Air models.

I doubt that there's much point in ranting about it here, or anywhere else. Adjust your expectations, or sell your computer to someone who doesn't use it much.

How can it be the expected behavior, I recently bought a MSI Wind with an Intel Atom 1.6Gz, this little machine can process video better than my MacBook Air. Intel developed this custom chip for Apple in order to not sacrifice performance compared to another MacBook (according to Steve Jobs Keynote). So we need an answer from Apple about this underperforming machine, that is really frustrating to use.

Yesterday and some time before i've got the same issue with kernel_task using more then 150%. MBA was really slow. In console i didn't found anything interesting.

After some time i've got "loading" mouse arrow on every app, unable to do anything and had to hard reset. I was unable to find out what caused this system failure, because all the records in console related to this time had disappeared.

Having read that this problem is heat-related i've done two things:First, i've installed onyx to clean the system.Second, i've ported my cpu-intensive app to mac, which i used before to heat up faulty nvidia 8400 chip by cpu in dell to return it to normal state. As for now this app is running for about 5 hours using about 150% of cpu (up to 360% (???) according to top). kernel_task is at 2% and there is no evidence of slowdown. Onyx reports cpu works at full 1.6 ghz. I can share source code or binary, anyway it generates nice fractal video.

So i can state that this problem is not heat-related, but something else resulting in overheating as side effect. And it was either fixed by onyx or didn't appear at the time. The two suspicious things are 3rd party programs (like cpu temperature monitors and tweaks) or intensive use of network. If any network intensive program like transmission creates lots of connections or I have bunch of tabs in safari then kernel_task is very active.

I have the same problem, except my bottom core on the activity monitor does not drop out ever. The kernal_task gets pegged above 100% around 130 (how could that be possible??) and the compter basically gets really hot, the fans kick on and you cant really do much with it because it is really slow.

Besides that, the computer needs to be shut down. I just tried closing the lid and opening it back up, and that seems to be a quick work around.

This usually happens to me while i am programming for Arduino using the USB adapter. I used to get the syslog error where the syslog gets too big, then that pegs the cpu, but now every time I load my computer, I disable the logging.

It also happens when I do something intensive like VMware. I am running windows7 on vmware, and booting that up can peg the kernal_task... it never recovers. I have to have they system in an ideal cold, quiet state, before booting vmware, then only suspend the guest os.

Its sad to know that this is an issue with the New macbook air too!! as i am running the original one.

Unfortunately I'm still having these issues. A reformat and replacement of the computer have helped a lot, but pretty much every Skype video call still brings the computer to a grinding slowdown. I've stopped trying to run Parallels altogether.

I've noticed a large lack of knowledge about this problem on Apple's part. My last visit to the Apple store's Genius bar had me waiting over an hour because the guy just couldn't believe that the problem exists. I wonder sometimes if I'm the only one who routinely can't use his laptop!

I'm curious to know how many people have this problem. I've put up a photo album up here:

to post screenshots of Activity Monitor showing kernel_task taking up 100%+ of the CPU's time. If you experience this problem together with the slowdowns, hit ShiftCMD3 or ShiftCMD4 and upload the picture of Activity Monitor. It's interesting to see that the applications running aren't really very taxing either - I've got safari, Adium, Netnewswire, etc, but nothing major other than that.

Right now I'm copying about 15 gig of data to an external 2,5 HD and the kernel_task uses two times 100%. (I have menumeters installed to control my processor speed)

Firefox, Textedit are the only open applications.

I just flew to Asia from Germany. In Germany it was very cold and I didn't have the problem. (At least I didn't realize it the first few days I had the new MBA) Here it's about 25° Celsius (75 F) and I'm having the

"Uah! kernel_task again! I can't work with this computer" issue all the time having the urge to throw it out of the window.

How dare they sell such a machine?

After the fiasco with the first gen MBA I thought they fixed the problem with the second gen, because every honest company would rather stop making the product than selling something broken, but...

I lost all the trust in this company and I have been a loyal costumer for more than 13 years. Can apple please do something about that?

I have been using an MBA as my main work machine since May. I run Lotus Notes, Excel, Firefox, Word, and Powerpoint all at once or a subset of them all day, everyday. I'd hardly say this was a heavy load, most of the apps, most of the time, run at less than 50% CPU and only in bursts, most of the time the machine is idling. As I am writing this the top CPU task is running between 7 and 10%, overall usage is less than 50%.

The machine typically runs at 60-68C+ and with the fans at 6200RPM - whether it's on battery or mains, whether or not I have anything plugged in to the USB or mini-DVI. IMHO these are what distractions and not part of the problems.

I have seen the wild kernel_task for most of the time I have had the machine and it doesn't seem to be at all predictable. My office is cool, the MBA has no obstructions around the vents and it can go wild when it is idling, it doesn't need a load.

Up until about an hour ago I had not tried running an external fan to blow air across the vents on the back of the machine. It has a very noticable effect - the machine is now running at 50-55C and the fans are at ------- 2500 !!!!

So, what's the problem - not enough physical cooling - so I will be building a little stand for it at work with a silent fan underneath - for now......

I'm also using the external fan solution. What I have found, if you can trust iStat Pro, is that the best indicator of the kernel_task problem is the enclosure base temperature. If that gets above 40C, the computer slows down. It has little to do with CPU temperature. But the fan solution is not perfect. Yesterday I used iMovie/iDVD and the kernel_task went wild, although I had my fan running. Then I closed down the computer and let it cool down, started iDVD again with the fan on right from the start, and then it was able to run for an hour encoding without kernel_task going crazy. I interpret this so that when I started using iMovie first time, I had already used the computer for some time, and although that was for non-CPU intensive tasks, it heated the computer enough that when I started using iMovie it just was too much. Second time I used the fan right from the start, and that allowed the computer to stay cool during the whole encoding process.

But it is really unacceptable that you cannot even use iLife programs on the MBA without installing external fans or working in a freezer.

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